The only problem with that is you sign tucker and bo, and aim to reduce payroll naturally next year. Who is playing centre field? You then need to go sign a free agent next year there or extend varsho. I wouldn't put barger in the same category as he is cost controlled for a long time. He is a guy i'd be extremely reluctant to trade unless i was blown away.
Berrios, Santander and Rodriquez aren't really assets currently. I can see why you'd trade Berrios as he will have 10-5 rights and a full no trade in july. But i don't see why we'd trade the other two. We aren't getting anything back and they are useful to some extent. Why not give them a chance to have a big year and then trade them? If Santander hits 40 bombs this year, you could probably trade that deal, or just have a DH.
The players that might get you something back, and who we might not need need this season are guys like varsho, schneider, lukes and lauer. I'd personally lean varsho and lauer as they have a single year of control. I'd be willing to trade schneider but maybe more reticent on lukes.